1.1 Biopsychology

Question 1

What is the nervous system?

Answer 1

A specialized network of cells in the human body that act as our primary internal communication system

Question 2

What are the 2 subsystems of the nervous system?

Answer 2

• Central nervous system (CNS)
• Peripheral nervous system (PNS)

Question 3

What are the 2 main functions of the nervous system?

Answer 3

• To collect, process and respond to information in the environment
• To co-ordinate the working of different organs and cells in the body

Question 4

What is the central nervous system (CNS)?

Answer 4

Consists of the brain and the spinal cord and is the origin of all complex commands and decisions

Question 5

What is the peripheral nervous system (PNS)?

Answer 5

Sends information to the CNS from the environment, and transmits messages from the CNS to muscles and glands in the body

Question 6

What are the 2 subdivisions of the PNS?

Answer 6

• Autonomic nervous system (ANS)
• Somatic nervous system (SNS)

Question 7

What is the role of the somatic nervous system (SNS)?

Answer 7

Governs muscle movement and receives information from sensory receptors

Question 8

What is the role of the autonomic nervous system (ANS)?

Answer 8

Governs vital functions in the body such as breathing, heart rate, digestion, sexual arousal and stress responses

Question 9

What is the endocrine system?

Answer 9

A network of glands across the body that secretes hormones + works alongside nervous system

Question 10

Name the 8 main glands in the endocrine system

Answer 10

• Hypothalamus
• Pituitary
• Thyroid
• Parathyroid
• Adrenals
• Pancreas
• Ovaries
  -Testes

Question 11

What is the role of the pituitary gland and where is it located?

Answer 11

• Located in the brain
• Controls the release of hormones from all other endocrine glands in the body (‘master gland’)

Question 12

What is the role of the thyroid gland?

Answer 12

Releases thyroxine which affects cells in the heart (increases heart rate) and throughout the body (increases metabolic rates), therefore affects growth rates

Question 13

Describe how the endocrine system and ANS work together

Answer 13

• When a stressor is perceived, the hypothalamus activates the pituitary gland triggering activity in the sympathetic branch of the ANS
• ANS changes from its normal parasympathetic state to its psychologically aroused state sympathetic
• ‘Fight or flight’ is triggered

Question 14

What is the difference between the parasympathetic state and the sympathetic state?

Answer 14

• Parasympathetic is the body’s normal state when it is relaxed, resting or feeding
• Sympathetic is a state of physiological arousal, preparing the body for fight or flight

Question 15

What is adrenaline and its purpose?

Answer 15

• A stress hormone (released from the adrenal medulla)
• Triggers physiological changes in the body e.g heart rate creating the arousal necessary for fight or flight

Question 16

What is a gland?

Answer 16

An organ in the body that synthesises substances such a as hormones

Question 17

What is a hormone?

Answer 17

Chemical messengers released from endocrine glands that circulate the blood but only affect target organs

Question 18

What is the role of the parasympathetic nervous system?

Answer 18

Returns the body to its natural resting state, acting as a brake and reducing the activities of the body that were increased by the sympathetic branch (reset and digest response)

Question 19

What are 3 features of the parasympathetic state?

Answer 19

• Decreases heart and breathing rate
• Stimulates digestion
• Constricts pupils

Question 20

What are 3 features of the sympathetic state?

Answer 20

• Increased heart and breathing rate
• Inhibits digestion
• Dilates pupils

Question 21

How does the PNS transmit messages?

Answer 21

Via millions of neurons

Question 22

What is the main difference between the nervous system and endocrine system

Answer 22

- Nervous system: based on electrical and chemical signals
- Endocrine system: based on hormones

Question 23

What is the function of the spinal cord?

Answer 23

An extension of the brain. Passes messages to and from the brain and connects nerves to PNS

Question 24

What is the outer layer of the brain called?

Answer 24

Cerebral cortex (only 3mm thick)

Question 25

Describe the role of the endocrine system

Answer 25

Instructs glands to release hormones directly into the bloodstream. These hormones are carried towards target organs in the body.

Question 26

What are neurons?

Answer 26

Nerve cells that process and transmits messages through electrical and chemical signals

Question 27

What are the 3 types of neurons?

Answer 27

- Sensory neuron - Relay neuron - Motor neuron

Question 28

State the 2 ways neurons transmit signals?

Answer 28

- Signals within neurons transmitted electrically - Signals between neurons transmitted chemically

Question 29

Describe the features of a sensory neuron, its role and where its located?

Answer 29

- Long dendrites and short axons - Carry messages from the PNS to the CNS - Located in receptors such as eyes and ears

Question 30

Describe the features of a relay neuron, its role and where its located?

Answer 30

- Short dendrites and short axons - Connect the sensory neurons to the motor and other neurons - Located in the brain and spinal cord

Question 31

Describe the features of a motor neuron, its role and where its located?

Answer 31

- Short dendrites and long axons - Connects the CNS to effectors such as muscles and glands - Located in the CNS

Question 32

Name the features of a neuron

Answer 32

- Cell body: Includes a nucleus, genetic material - Dendrites: branch-like structures that protrude from the cell body - Axon - Nodes of Ranvier - Terminal buttons

Question 33

What is the role of dendrites?

Answer 33

To carry nerve impulses from neighbouring neurons towards the cell body

Question 34

What is the purpose of a myelin sheath?

Answer 34

Protects the axon and speeds up electrical transmission of the impulse

Question 35

What is the role of the axon?

Answer 35

Carries impulses away from the cell body down the length of the neuron

Question 36

What is the role of the nodes of Ranvier?

Answer 36

Speed up the transmission of the impulse by forcing it to 'jump' across the gaps along the axon

Question 37

What is the role of terminal buttons?

Answer 37

Communicate with the next neuron in the chain across the synapse

Question 38

Describe the process of electrical transmission

Answer 38

- When the inside of the cell is negatively charged compared to the outside (as the neuron is in its resting state) - When the neuron is activated by a stimulus, it becomes positively charged causing action potential to occur - Creates an electrical impulse that travels towards the end of the neuron

Question 39

What is synaptic transmission?

Answer 39

The process by which neighbouring neurons communicate with each other by sending chemical messages across the synapse

Question 40

What is a neurotransmitter?

Answer 40

Chemicals that diffuse across the synapse, allowing neurons in the body to communicate with each other

Question 41

What is excitation and what does it lead to?

Answer 41

- When a neurotransmitter increases the positive charge of the postsynaptic neuron - Increases the likelihood that the postsynaptic neuron will pass on the electrical impulse

Question 42

What is inhibition and what does it lead to?

Answer 42

- When a neurotransmitter increases the negative charge of the postsynaptic neuron - Decreases the likelihood that the postsynaptic neuron will pass on the electrical impulse

Question 43

What happens when an electrical impulse reaches the end of a neuron?

Answer 43

It triggers the release of the neurotransmitter from tiny sacks called synaptic vesicles

Question 44

Describe the process of summation

Answer 44

- The excitatory and inhibitory influences are summed, the net effect affects the likelihood of what occurs - The action potential is only triggered if the sum of excitatory or inhibitory signals at any one time reaches the threshold

Question 45

Describe the process of synaptic transmission

Answer 45

- When an electrical impulse arrives on the presynaptic neuron, neurotransmitters are released from synaptic vesicles - The neurotransmitters diffuse across the synaptic cleft and bind to the postsynaptic receptor sites - The chemical message is converted into an electrical impulse and the process begins again